Diseases associated with mandibular third molar teeth

Dentists' perception of third molar surgery in the Kingdom of Saudi Arabia: A cross sectional pilot study

Background/purpose

Concerns about the indications for the surgical removal of third molars have not yet reached a decisive agreement. The aim of the study was to evaluate the perception and practice of Saudi' dentists when encountering third molars clinical situations including diagnosis, treatment, and postsurgical care.

Materials and methods

A cross-sectional survey was conducted and approved by the ethics research committee at Prince Sattam Bin Abdulaziz (PSAU). The survey comprised of four sets of questions with multiple-choice answers including the participants' details and type of practice (private or government), clinical awareness and attitude regarding lower third molars surgery, and the confidence level of dentists when performing third molars extraction. The survey was published online with a timeframe of three months to respond.

Results

196 participants responded to the designated survey (55 dental interns and 141 general dental practitioners (GPs)). Most responses (80.1%) were from Riyadh province (central region). There was a significant difference between GPs and interns in terms of impacted third molars with associated cystic lesions, bony impactions, and diffuse pain (P < 0.05). Male dentists tend to prescribe antibiotics more than female dentists (P = 0.001) and GPs more than interns (P = 0.027). The results also indicated that male dentists were more confident than females when performing third molar extraction. Generally, female dentists preferred to have further training on such surgery (P < 0.05).

Conclusion

Continuing professional development programs both during dental internship and general practice are recommended to improve the required skills of third molar extraction.

Radiographic Features of Mandibular Second Molars with Eruption Disturbances: A Retrospective Study

We aimed to establish the characteristics and potential etiological risk factors of eruption disturbances in mandibular second molars (MM2). We retrospectively enrolled patients with eruption disturbances in MM2. A total of 143 MM2 with eruption disturbances from 112 patients (mean age 17.45 ± 6.35) were included in this study. Panoramic radiographs were employed to determine the risk factor, angulation type, impaction depth, tooth development stage, and associated pathology. The novel classification method of MM2 was based on impaction depth and angulation. Of 143 MM2, 137 and 6 were diagnosed with impaction and retention, respectively. Insufficient space was the most frequent risk factor for eruption disturbances. There were no significant differences between retention and impaction regarding sex, age, or side. The most frequent impaction type was Type I. The most frequent angulation of impacted MM2 was mesioangular. Impacted MM2 with shallower depth were more frequently associated with the presence of first molar undercut. Impaction types did not differ according to age, side, development stage, or distance from the MM1 distal surface to the anterior border of the ramus. Dentigerous cysts were associated with earlier MM2 development stages and greater MM2 depth. In conclusion, MM2 impaction types differed according to the risk factor, angulation type, MM1 undercut, and presence of cysts. Early MM2 development stage and greater MM2 depth were risk factors for MM2 eruption disturbances with cysts.

Visibility of anatomical landmarks in the region of the mandibular third molar, a comparison between a low-dose and default protocol of CBCT

OBJECTIVE

Optimization of radiographic examinations is essential for radiation protection. The objective of the study was to investigate the clinical applicability of a low-dose CBCT protocol as compared to the default for pre-surgical evaluation of mandibular third molars.

MATERIAL & METHODS

Forty-eight patients (62 teeth) referred for pre-surgical mandibular third molar investigation were recruited after justification for CBCT. Two CBCT scans of each site were made using a default protocol and a low-dose protocol (Veraviewepocs 3D F40, J Morita Corp, Kyoto, Japan). The low-dose protocol had the same tube potential (90 kV) and exposure time (9.4 s) as the default, but with reduced tube current, from 5 mA to 2 mA. Four observers evaluated the visibility of five relevant anatomical variables. Image quality was ranked on a 3-point scale as diagnostically acceptable, doubtful, or unacceptable. The Wilcoxon signed-rank test compared differences between the two protocols. The significance level was set at p ≤ .05.

RESULTS

No significant differences were found between the two protocols for any observer regarding the visibility of the relationship and proximity between the roots and the mandibular canal; root morphology; and possible root resorption of the second molar. The periodontal ligament differed significantly in visibility between the two protocols (p ≤ .05).

CONCLUSIONS

This study indicates that a low-dose CBCT protocol with a 60% reduction of the tube current provides, in most cases, acceptable image quality for pre-surgical assessment of mandibular third molars. Optimization of CBCT protocols should be a priority according to recommended guidelines.

Application of sequential multimodal analgesia before and after impacted mandibular third molar extraction: Protocol for a randomized controlled trial

Background

Several analgesics have been applied under various protocols to control the moderate-to-severe postoperative pain caused by the surgical extraction of an impacted mandibular third molar. However, a consensus on optimal pain management while minimizing side effects is yet to be reached.

Methods

This multi-center, prospective, double-blind, randomized controlled trial aims to evaluate the efficacy and safety of sequential multimodal analgesia combined with postoperative zaltoprofen along with multiple preemptive analgesics. A total of 80 participants with bilateral impacted mandibular third molar from two hospitals were randomized into two groups. Two surgical extractions were performed at one-month intervals, and in a crossover design, celecoxib or tramadol/acetaminophen was administered before one extraction and placebo before the other extraction. Following extraction, all subjects took zaltoprofen for 5 days. The outcome measures included pain at specific times, time and intensity of the first pain onset after extraction, need of rescue drugs, and occurrence and frequency of side effects.

Conclusions

This ongoing clinical trial was designed to provide evidence regarding a new protocol for effective postoperative pain management of a commonly performed surgical extraction. The results of this study will provide guidance to clinicians regarding the timing and combination of oral analgesics in various oral surgeries performed under local anesthesia.

Trial registration

KCT0005450, registered on October 7, 2020.

The pattern of mandibular third molar impaction and its relationship with the development of distal caries in adjacent second molars among Emiratis: a retrospective study

Objectives

The purpose of this study was to investigate the pattern of mandibular third molar (MTM) impaction and associated carious lesions in adjacent mandibular second molars (MSMs) in a sample of Emirati individuals.

Methods

This retrospective study assessed 2000 orthopantomograms of Emirati patients who visited the Specialized Fujairah Dental Center between 2015 and 2020. The depth, ramus relation and angulation of the impacted MTMs were assessed according to the Pell and Gregory classification and Winter’s classification. In addition, carious lesions in adjacent MSMs associated with the evaluated parameters were identified.

Results

A total of 461 (23.05%) of the patients had at least one impacted MTM. The mean age of the study population was 26.24 years. Mesioangular, level B, and class II impactions were the most common, at 47.37% (χ² = 382.134; p < 0.001), 45.48% (χ² = 56.889; p < 0.001), and 74.05% (χ² = 513.099; p < 0.001), respectively. There was a higher percentage of level C impaction among females than among males (χ² = 19.178; p < 0.001). A total of 126 impacted teeth (18.36%) had associated carious lesions. These carious lesions were predominantly found in teeth with mesioangular impactions (χ² = 59.430; p < 0.001), level A and B impactions (χ² = 23.301; p < 0.001), and class II and I impactions (χ² = 17.918; p = 0.006).

Conclusions

It is imperative to raise awareness of soft tissue mesioangular-impacted MTMs, as they are the most frequently associated with the development of carious lesions in adjacent MSMs. Approximately one quarter of evaluated Emiratis had at least one impacted MTM, with the most prevalent pattern being class II, level B, and mesioangular impactions. Furthermore, surgical removal is expected to be more challenging for females than for males.

Anatomical Positions of Mesially/Horizontally Impacted Mandibular Third Molars are Significant Predictors for Distal Caries in Adjacent Second Molars

Background

Prevalence of distal caries in mandibular second molars (M2Ms) and its relationship with impacted condition of the adjacent mandibular third molars (M3Ms) have been reported in some studies. The results, however, were ambiguous because of including all impaction types and using univariate analysis for statistics.

Aim

This study aimed to determine anatomical features of mesially/horizontally impacted mandibular third molars (M3Ms) that could predict distal caries in the adjacent mandibular second molars (M2Ms) using multivariable analysis.

Materials and Methods

The study sample consisted of 300 digital panoramic radiographs of patients who underwent impacted M3Ms extraction. Two independent researchers collected the following variables from 446 pairs of M2M-M3M: sex, age, status of distal caries in M2Ms, mesial angulation, and Pell–Gregory classification of M3Ms.

Results

The prevalence of distal caries was 50.67%. Multivariable Firth's logistic regression analysis showed that age (β = 0.066, 95% CI = 0.023–0.113), mesial angulation (<30°: β = −1.205, 95% CI = −1.955 to −0.499; >70°: β = −0.730, 95% CI = −1.184 to −0.282), vertical position (level B: β = 2.275; 95% CI = 0.015–7.175; level A: β = 3.008; 95% CI = 0.755–7.905), and horizontal position (level II: β = 1.515; 95% CI = 0.444–2.874; level I: β = 1.423; 95% CI = 0.283–2.825) were significant variables after adjusting for sex in the final model for predicting distal caries (p < 0.05).

Conclusions

In conclusion, anatomical positions of impacted M3Ms, such as mesial angulation and Pell–Gregory classification were significant predictors of distal caries in M2Ms.

To prophylactically extract or not to extract partially erupted mesio-angularly impacted lower third molars?

Introduction Prophylactic removal of mesio-angularly impacted mandibular third molars (MAIM3Ms) has been discouraged by the National Institute for Health and Care Excellence in 2000. Consequently, partially erupted MAIM3Ms are retained for longer and only extracted if complications arise. The debate whether to extract prophylactically or to monitor these teeth is ongoing.Pathologies associated with retained partially erupted MAIM3Ms Retaining third molars long into adulthood has been associated with an increased risk of distal cervical caries and external root resorption of the second molar, periodontal disease and pericoronitis, among other pathologies. Although watchful monitoring can help to identify these pathologies, their nature often leads not only to a poor prognosis for the third molar, but also for the second molar, which then requires costly and time-consuming restorative or even prosthodontic work.Considering prophylactic extractions While an individual risk assessment is paramount, prophylactic removal of partially erupted MAIM3Ms has been shown to have positive effects on oral health-related quality of life, to relieve the pressure on secondary care services and to be economically feasible for the NHS.Conclusion While long-term prospective cohort studies are necessary to put an end to the ongoing controversy, patients' needs and wishes should be at the forefront of the provision of care.

[Characterization of third molar extraction]

The aim of this study was to characterize the main indications, contraindications and prophylactic actions for third molar extraction according to the literature. The Pubmed, Scopus and Web of Science databases were searched using a total of 3 search keys, including publications up to 5 years old, in English or Spanish, with availability of full text. Eighteen articles were selected and showed that the most frequent indication for third molar extraction was the diagnosis of pericoronaritis, followed by distal cervical caries in the lower second molar, and root resorption in adjacent teeth and cysts. In turn, it may be indicated to facilitate other types of dental treatment, such as orthodontics, orthognathic surgery and rehabilitation. In relation to contraindications, the risk of intraoperative complications was associated with the inferior alveolar nerve, advanced age and the predomination of systemic involvement. Prophylactic extraction was included in the analysis in 72.2% of the articles, with a predominance of exodontia of asymptomatic and disease-free third molars. Finally, there are clear indications and contraindications for third molar extraction, being mainly associated with pathological changes, indications for orthodontic treatment, orthognathic surgery and rehabilitative treatment. However, there is controversy in the literature regarding prophylactic extraction, emphasizing that not all retained and asymptomatic third molars should be extracted. Third molar extraction should be evaluated on a case by case basis, considering the benefits, the patient's characteristics and the risk of postoperative complications.

A Review of Evidence-Based Recommendations for Pericoronitis Management and a Systematic Review of Antibiotic Prescribing for Pericoronitis among Dentists: Inappropriate Pericoronitis Treatment Is a Critical Factor of Antibiotic Overuse in Dentistry

This work provides a narrative review covering evidence-based recommendations for pericoronitis management (Part A) and a systematic review of antibiotic prescribing for pericoronitis from January 2000 to May 2021 (Part B). Part A presents the most recent, clinically significant, and evidence-based guidance for pericoronitis diagnosis and proper treatment recommending the local therapy over antibiotic prescribing, which should be reserved for severe conditions. The systematic review includes publications analyzing sets of patients treated for pericoronitis and questionnaires that identified dentists’ therapeutic approaches to pericoronitis. Questionnaires among dentists revealed that almost 75% of them prescribed antibiotics for pericoronitis, and pericoronitis was among the top 4 in the frequency of antibiotic use within the surveyed diagnoses and situations. Studies involving patients showed that antibiotics were prescribed to more than half of the patients with pericoronitis, and pericoronitis was among the top 2 in the frequency of antibiotic use within the monitored diagnoses and situations. The most prescribed antibiotics for pericoronitis were amoxicillin and metronidazole. The systematic review results show abundant and unnecessary use of antibiotics for pericoronitis and are in strong contrast to evidence-based recommendations summarized in the narrative review. Adherence of dental professionals to the recommendations presented in this work can help rapidly reduce the duration of pericoronitis, prevent its complications, and reduce the use of antibiotics and thus reduce its impact on patients’ quality of life, healthcare costs, and antimicrobial resistance development.

The association of mandibular third molar impaction with the dental and periodontal lesions in the adjacent second molars

BACKGROUND

It is a consensus that symptomatic impacted mandibular third molars (MTMs) need to be removed. Although the prophylactic extraction of asymptomatic impacted MTMs remains controversial. This study aims to investigate the effects of MTMs on themselves and adjacent teeth pathophysiology and provide the evidence for prophylactic extraction of impacted MTMs.

METHODS

A retrospective study of panoramic radiographs of patients visited the Affiliated Stomatology Hospital of Guangzhou Medical University from April 2014 to May 2018 was conducted to investigate the dental and periodontal lesions in MTMs and adjacent mandibular second molars (MSMs), as well as the correlation of tooth lesion severity with patient age.

RESULTS

Among the 2650 impacted MTMs, 6.98% dental lesions and 37.81% periodontal lesions were found, as well as 24.63% dental lesions and 35.30% periodontal lesions in the distal of adjacent MSMs. 9.27%, 2.02%, 0.47%, and 13.33% dental lesions and 48.81%, 17.31%, 5.19%, and 10% periodontal lesions were observed in MTMs with mesioangular, horizontal, inverted and distoangular impaction types, respectively. For the adjacent MSMs, 31.98%, 11.82%, 1.94%, and 13.33% distal dental lesions and 45.74%, 16.95%, 2.91%, and 23.33% distal periodontal lesions were found in mesioangular, horizontal, inverted and distoangular impaction types, respectively. In mesioangular MTMs, the severity of the distal dental and periodontal lesions in the adjacent MSMs showed a high-positive correlation with patient age (P < 0.05) CONCLUSION: Early prophylactic extraction of MTMs with mesioangular-impaction and close monitoring of MTMs with horizontal/inverted-impaction could prevent impacted MTMs-associated lesions in MTMs/MSMs.

The Retromolar Space and Wisdom Teeth in Humans: Reasons for Surgical Tooth Extraction

OBJECTIVE

 This article explores the problem of developing pathologies in the retromolar region. Findings can serve a framework for disease prevention and for the improvement of the quality of life of patients. The present study aims to justify the possibility of utilizing morphometric methods to foresee problems in the eruption of third molars.

MATERIALS AND METHODS

 A comprehensive morphometric study of the lower jaw and facial skeleton involves 100 skulls of Homo sapiens to identify the anatomical causes of problems with wisdom teeth eruption. All said skulls are divided in two groups: I: skulls with intact dentition; II: skulls with impacted third molars.

RESULTS

 This work allows detecting abnormalities in the eruption of the third molar with high probability of success. The abnormalities in point are considered not only those associated with the generally accepted parameters but also those that occur in the leptoprosopic face cases.

CONCLUSIONS

 Face type and the structural features of the facial skeleton play a significant role in the abnormal eruption of the lower third molar.

Surgical techniques for the removal of mandibular wisdom teeth

BACKGROUND

Pathology relating to mandibular wisdom teeth is a frequent presentation to oral and maxillofacial surgeons, and surgical removal of mandibular wisdom teeth is a common operation. The indications for surgical removal of these teeth are alleviation of local pain, swelling and trismus, and also the prevention of spread of infection that may occasionally threaten life. Surgery is commonly associated with short-term postoperative pain, swelling and trismus. Less frequently, infection, dry socket (alveolar osteitis) and trigeminal nerve injuries may occur. This review focuses on the optimal methods in order to improve patient experience and minimise postoperative morbidity.

OBJECTIVES

To compare the relative benefits and risks of different techniques for surgical removal of mandibular wisdom teeth.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health Trials Register (to 8 July 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; 2019, Issue 6), MEDLINE Ovid (1946 to 8 July 2019), and Embase Ovid (1980 to 8 July 2019). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. We placed no restrictions on the language or date of publication.

SELECTION CRITERIA

Randomised controlled trials comparing different surgical techniques for the removal of mandibular wisdom teeth.

DATA COLLECTION AND ANALYSIS

Three review authors were involved in assessing the relevance of identified studies, evaluated the risk of bias in included studies and extracted data. We used risk ratios (RRs) for dichotomous data in parallel-group trials (or Peto odds ratios if the event rate was low), odds ratios (ORs) for dichotomous data in cross-over or split-mouth studies, and mean differences (MDs) for continuous data. We took into account the pairing of the split-mouth studies in our analyses, and combined parallel-group and split-mouth studies using the generic inverse-variance method. We used the fixed-effect model for three studies or fewer, and random-effects model for more than three studies.

MAIN RESULTS

We included 62 trials with 4643 participants. Several of the trials excluded individuals who were not in excellent health. We assessed 33 of the studies (53%) as being at high risk of bias and 29 as unclear. We report results for our primary outcomes below. Comparisons of different suturing techniques and of drain versus no drain did not report any of our primary outcomes. No studies provided useable data for any of our primary outcomes in relation to coronectomy. There is insufficient evidence to determine whether envelope or triangular flap designs led to more alveolar osteitis (OR 0.33, 95% confidence interval (CI) 0.09 to 1.23; 5 studies; low-certainty evidence), wound infection (OR 0.29, 95% CI 0.04 to 2.06; 2 studies; low-certainty evidence), or permanent altered tongue sensation (Peto OR 4.48, 95% CI 0.07 to 286.49; 1 study; very low-certainty evidence). In terms of other adverse effects, two studies reported wound dehiscence at up to 30 days after surgery, but found no difference in risk between interventions. There is insufficient evidence to determine whether the use of a lingual retractor affected the risk of permanent altered sensation compared to not using one (Peto OR 0.14, 95% CI 0.00 to 6.82; 1 study; very low-certainty evidence). None of our other primary outcomes were reported by studies included in this comparison. There is insufficient evidence to determine whether lingual split with chisel is better than a surgical hand-piece for bone removal in terms of wound infection (OR 1.00, 95% CI 0.31 to 3.21; 1 study; very low-certainty evidence). Alveolar osteitis, permanent altered sensation, and other adverse effects were not reported. There is insufficient evidence to determine whether there is any difference in alveolar osteitis according to irrigation method (mechanical versus manual: RR 0.33, 95% CI 0.01 to 8.09; 1 study) or irrigation volume (high versus low; RR 0.52, 95% CI 0.27 to 1.02; 1 study), or whether there is any difference in postoperative infection according to irrigation method (mechanical versus manual: RR 0.50, 95% CI 0.05 to 5.43; 1 study) or irrigation volume (low versus high; RR 0.17, 95% CI 0.02 to 1.37; 1 study) (all very low-certainty evidence). These studies did not report permanent altered sensation and adverse effects. There is insufficient evidence to determine whether primary or secondary wound closure led to more alveolar osteitis (RR 0.99, 95% CI 0.41 to 2.40; 3 studies; low-certainty evidence), wound infection (RR 4.77, 95% CI 0.24 to 96.34; 1 study; very low-certainty evidence), or adverse effects (bleeding) (RR 0.41, 95% CI 0.11 to 1.47; 1 study; very low-certainty evidence). These studies did not report permanent sensation changes. Placing platelet rich plasma (PRP) or platelet rich fibrin (PRF) in sockets may reduce the incidence of alveolar osteitis (OR 0.39, 95% CI 0.22 to 0.67; 2 studies), but the evidence is of low certainty. Our other primary outcomes were not reported.

AUTHORS' CONCLUSIONS

In this 2020 update, we added 27 new studies to the original 35 in the 2014 review. Unfortunately, even with the addition of these studies, we have been unable to draw many meaningful conclusions. The small number of trials evaluating each comparison and reporting our primary outcomes, along with methodological biases in the included trials, means that the body of evidence for each of the nine comparisons evaluated is of low or very low certainty. Participant populations in the trials may not be representative of the general population, or even the population undergoing third molar surgery. Many trials excluded individuals who were not in good health, and several excluded those with active infection or who had deep impactions of their third molars. Consequently, we are unable to make firm recommendations to surgeons to inform their techniques for removal of mandibular third molars. The evidence is uncertain, though we note that there is some limited evidence that placing PRP or PRF in sockets may reduce the incidence of dry socket. The evidence provided in this review may be used as a guide for surgeons when selecting and refining their surgical techniques. Ongoing studies may allow us to provide more definitive conclusions in the future.

A systematic review of second molar distal surface caries incidence in the context of third molar absence and emergence

Objective The aim of this systematic review was to gain a greater insight into the incidence rates of distal surface caries (DSC) on second permanent molars.Data sources A literature search using the Cochrane Library, Lilacs, Embase and Medline via Ovid retrieved English and non-English language articles from inception to June 2016. The electronic searches were supplemented with reference searching and citation tracking. Reviewers independently and in duplicate performed data extraction and completed structured quality assessments using a validated risk of bias tool for observational studies and categorised the summary scores.Data selection The search yielded 81 records and, after application of inclusion and exclusion criteria, two incidence studies were included in this systematic review.Data extraction The DSC incidence was reported in one study as relative risk (RR = 2.53; 95% CI, 1.55 to 4.14) adjacent to erupted, (RR = 0.83; 95% CI, 0.11 to 6.04) soft tissue impacted and (RR = 1.44; 95% CI, 0.55 to 3.72) bony impacted third molars in comparison to when the third molar was absent with a 25-year follow-up. The second study reported a DSC incidence of 100 surface-years (1% of all sites) with an 18-month follow-up period.Conclusions Both cohort studies indicated that DSC incidence was higher when third molars were erupted in the intermediate term, but greater over the long term for an ageing male population. However, further high-quality research is required to improve the accuracy of these findings.

Prevalence of impacted teeth among a sample of Yemeni population and their association with sex and age

Aim: the aim of the study was to assess the prevalence of impacted teeth and its association with sex and age among a sample of the Yemeni population. Materials and Methods: A cross sectional study design was employed. The study included 999 radiographical records of patients who had panoramic X- rays previously done. All radiographs were assessed for the number and type of impacted teeth, pathology-associated impaction, sex, age and location (mandible and/or maxilla). The collected data was analyzed using SPSS®version21 software. Results: The study sample comprised digital panoramic radiographs of Yemeni patients aged 17 to 54 years (mean 26.6 years). The present study found 542 patients (54.3%) presented with at least one impacted tooth. The 17 to 25 years age group of the study sample had the highest prevalence of tooth impaction (28.6%). Only 10 (1.0%) case presented pathologies associated with the impacted teeth. There was a significant difference in the number of male 203 (20.3%) and female 339 (33.9%) patients with impacted teeth (p=0.031). Impacted teeth occurred slightly more often in the mandible (42.8%) compared to the maxilla (42.4%). Conclusion: The prevalence of impacted teeth among a sample of Yemeni population was high. Third molars and canines were the most common impacted teeth. The prevalence of impacted teeth in females was higher than in males and it was higher in the mandible than in the maxilla, with the younger patients with a higher prevalence of impaction.

Association between mandibular third molar position and the occurrence of pericoronitis: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to investigate the association between mandibular third molar position and occurrence of pericoronitis.

DESIGN

The systematic review was performed based on PRISMA criteria (Prospero: CRD42018102835). The electronic search was performed in Medline, Virtual Health Library and Web of Science (until August 2018), without language restriction. Two researchers independently selected studies, extracted data, and assessed methodologic quality. Twenty-one articles were included in the review, comprising 6895 patients, with 1913 third mandibular molars being affected by pericoronitis. Ten studies were incuded in meta-analysis.

RESULTS

The third molar in vertical position of Winter is the one with the greatest chance of presenting pericoronitis, compared to the other positions, while the horizontal position decreases this chance. There was no significant difference in the chance of pericoronitis between positions I and II of Pell & Gregory (OR: 0.29; IC: 0.07-1.23, I² = 88%). Third molars classified in position A had greater chance of pericoronitis when compared to those in position B (OR: 7.13; IC: 1.31-38.74, I² = 93%). The vertical position of the lower third molar is more associated with the occurrence of pericoronitis when compared to the other positions.

CONCLUSIONS

Vertical position of the lower third molar is more associated with the occurrence of pericoronitis when compared to the other Winter' positions. Considering Pell and Gregory positions, position A had a greater chance of pericoronitis compared to position B. The prophylactic removal of lower third semi-erupted vertical molar or in position A is indicated to prevent pericoronitis.

Characteristics of disease related to mesio-angular mandibular third molar teeth

The aim of this study was to identify the indications for the removal of mesio-angular mandibular third molars based on age and dental health as measured by the DMFT (decayed, missing, and filled teeth) score, and to find out if early intervention should be considered. We studied 319 patients who had 431 mesio-angular mandibular third molars removed. Variables recorded were age, primary indication for removal, and the DMFT score. Indications for removal included distal cervical caries (DCC) in the mandibular second molar (n=180, 44%), pericoronitis (n=131, 32%), and caries and related disease (n=62, 15%). The frequency of distal cervical caries (DCC) in the mandibular second molar increased linearly as patients became older and was the most common reason why mesio-angular third molar teeth were removed. This suggests that patients should be advised of the consequences of retaining thesetypes of third molars, and offered prophylactic removal of asymptomatic teeth.